1. Field of the Invention
The present invention relates to transceivers and IC packages. More specifically, the present invention relates to transceivers that can be directly plugged into an IC package.
2. Description of the Related Art
Known miniature transceivers include copper transceivers and optical transceivers. Optical transceivers are typically used for applications that require long signal transmissions or high data rates. However, known optical transceivers are expensive, and thus are not preferable for applications that do not require an optical connection, for example, applications with a short signal transmission length or applications that use low speed signals. Examples of known optical transceivers are disclosed in U.S. patent application Ser. Nos. 13/539,173; 61/504,072; and 61/636,005, the entire contents of which are hereby incorporated by reference. Much of the cost of these optical transceivers is due to the optical engines within the optical transceivers that convert light to electricity and electricity to light. Examples of the optical engines are disclosed in U.S. Pat. Nos. 7,329,054; 7,648,287; 7,766,559; and 7,824,112; U.S. Patent Application Publication Nos. 2008/0222351, 2011/0123150, and 2011/0123151; and U.S. Patent Application No. 61/562,371, the entire contents of which are hereby incorporated by reference.
In contrast, known copper transceivers are less expensive than known optical transceivers, but provide lower data rates and are typically unusable for longer signal transmissions. However, because known connectors are not designed to accept both optical transceivers and copper transceivers, a system that uses a known copper transceiver must be redesigned for use with an optical transceiver if it is desired to increase the data rate or signal transmission distance.
Furthermore, known copper transceivers have a number of known problems. Typically known copper transceivers include flying leads, which are typically only used for testing/debugging. In particular, known copper transceivers have impedance discontinuities in the cable termination region, that is, in the area where cable(s) are connected to a circuit board or other electrical components within the transceiver. The connection density in the cable termination region is also limited by the pitch of the cable(s) that are used with the transceiver. Further, thermoplastic housings often require screws and other hardware that add expense, and latching systems are often not very robust, which can lead to accidental disconnection of the transceiver.
Moreover, known transceivers use circuit boards that typically have a routing tolerance of +/−0.005″, which is not a tight enough tolerance to mate to a 0.5-mm pitch connector. Accordingly, the pitch of a typical connector used with known transceivers is typically at least 0.635 mm (0.025″).
One example of a known miniature transceiver is a Quad Small Form-factor Pluggable (QSFP or QSFP+) transceiver. QSFP transceivers are compact, hot-pluggable transceivers that include connectors that are designed to accept both copper and optical transceivers. However, a typical QSFP transceiver uses a relatively large receptacle cage and a mating connector with a 0.8 mm pitch, which results in the QSFP transceiver requiring a significant amount of space on the circuit board to which the QSFP transceiver is connected.
Transceiver size may be reduced and/or performance increased by using precision soldering or intricate hand soldering. However, these methods increase expense and may cause defects.
RF connectors or other expensive components may be included with a known miniature transceiver to improve performance. However, such connectors or components take up space on a circuit board or device to which the transceiver is to be connected and increase overall expense of the system that includes the transceiver. Similarly, custom or exotic fixtures may be used with a known miniature transceiver to improve performance. Such fixtures include, for example, components used in high-end vision systems or components manufactured using active alignment and registration automation (e.g., using laser alignment). However, such fixtures typically require expensive tooling, have complex design concerns, and have long set-up times for manufacturing, which increase overall expense of the system that includes the transceiver. Furthermore, custom or exotic fixtures are difficult and expensive to repair.
Snap features and press fit bosses have been used to secure known miniature transceivers in place. For example, a known miniature transceiver may include one or more pins that mechanically deform when inserted into corresponding holes of a known connector to secure the transceiver to the connector. However, these components are relatively unreliable and may lead to undesirable signal interruptions or mechanical failures. Friction latches have been used to secure known miniature transceivers in place. For example, a known connector may include one or more brackets that press against the sides of a known miniature transceiver to secure the transceiver to the connector. However, friction latches typically have a low withdrawal force, which allows transceivers to accidentally un-mate and cause transmission link failures or other system failures.
Termination-region density improvements have been made by using a cable with smaller gauge wires, which reduces pitch and increases density. However, using smaller gauge wires reduces performance of the transceiver, particularly by limiting data rate and signal transmission distance.
Furthermore, if conventional manufacturing methods are used to produce circuit boards with 0.5-mm pad pitches, high yield losses result due to the requirements for tolerances of the circuit boards. Accordingly, conventional manufacturing methods increase expense due to a high proportion of circuit boards rejected during sorting. In particular, conventional manufacturing methods often provide a yield of acceptable circuit boards that is several orders of magnitude lower than the rejected circuit boards.